Simple Interest
MCQs Math


Question:     What amount does Richard have to pay after 5 years if he takes a loan of $3600 at 6% simple interest?


Correct Answer  $4680

Solution And Explanation

Solution

Given,

Principal (P) = $3600

Rate of Simple Interest (SI) = 6%

Time (t) = 5 years

Thus, Amount (A) = ?

The Rate of Interest is always calculated per annum, i.e. per year.

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% per annum.

Method (1) Using Formula

Calculation of Simple Interest

Formula to Calculate Simple Interest

Simple Interest (SI) = Principal × Rate × Time

Thus, Simple Interest (SI) = $3600 × 6% × 5

= $3600 ×6/100 × 5

= 3600 × 6 × 5/100

= 21600 × 5/100

= 108000/100

= $1080

Thus, Simple Interest = $1080

Calculation of Amount

The total money paid to the lender by a borrower is called the Amount.

In other words, sum of priciple and interest is called the Amount.

Formula to Calculate the Amount

Amount = Principal + Interest

Thus, Amount = $3600 + $1080

= $4680

Thus, Amount to be paid = $4680 Answer

Method (2)

Calculation of Amount when Principal, Rate of Simple Interest and Time are given

Calculation of Amount directly using Principal, SI, and Time

Formula to calculate the Amount

Amount (A) = Principal (P) + Principal(P) × Rate of Interest (SI) × Time (t)

⇒ A = P + PRT

Here in the question, P = $3600

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 5 years

Thus, Amount (A)

= $3600 + ($3600 × 6% × 5)

= $3600 + ($3600 ×6/100 × 5)

= $3600 + (3600 × 6 × 5/100)

= $3600 + (21600 × 5/100)

= $3600 + (108000/100)

= $3600 + $1080 = $4680

Thus, Amount (A) to be paid = $4680 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = 6/100

∴ For $3600, the simple interest in 1 year

= 6/100 × 3600

= 6 × 3600/100

= 21600/100 = $216

Thus, simple interest for 1 year = $216

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $216 × 5 = $1080

Thus, Simple Interest (SI) = $1080

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3600 + $1080

= $4680

Thus, Amount to be paid = $4680 Answer


Similar Questions

(1) If Kenneth paid $6000 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(2) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 9% simple interest?

(3) What amount does Susan have to pay after 5 years if he takes a loan of $3650 at 2% simple interest?

(4) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 7% simple interest?

(5) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 6% simple interest.

(6) Find the amount to be paid if Charles borrowed a sum of $5900 at 5% simple interest for 7 years.

(7) Barbara took a loan of $5100 at the rate of 9% simple interest per annum. If he paid an amount of $9231 to clear the loan, then find the time period of the loan.

(8) James took a loan of $4000 at the rate of 6% simple interest per annum. If he paid an amount of $6160 to clear the loan, then find the time period of the loan.

(9) William took a loan of $5000 at the rate of 7% simple interest per annum. If he paid an amount of $8500 to clear the loan, then find the time period of the loan.

(10) Anthony had to pay $4558 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.


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